The Contractor shall conduct studies and investigations, as necessary, to provide suitable tissue preparation and staining techniques for the ultrastructural localization of the following enzyme activities in mineralized tissues of the rat jaw: Aryl sulfatase, 5'-Nucleotidase, Thiamine pyrophosphatase, and N-acetylglucosaminidase. Techniques shall also be presented for validating enzyme localization and identification of the associated cell types. The ultrastructural localization of such enzyme activities shall be consistent with the reported light microscope findings.